Continuing support is requested for the Radiotherapy Oncology Center at the Tufts-New England Medical Center. The Radiotherapy Oncology Center is devoted to clinical and basic research and to the teaching of problems related to the understanding and management of cancer, in addition to an extensive plan for outreach into the community. The research includes studies in the clinical diagnosis and treatment of cancer; radiobiology; physics and the application of computers to radiotherapy. The application consists of: 1) a description and rationale of the Radiotherapy Oncology Center; 2) a description of the existing facilities and equipment; 3) the tracing of the development and progress of the center and a presentation of its current and future activities; 4) an explanation of the network of joint and affiliated hospitals; and 5) a presentation of a 'master plan' of research and studies for the period of requested support.